--- title: I Let AI Rewrite 40% of My Codebase. Here’s What... description: A developer shares a first-hand account of delegating roughly 40% of a 60k-line Node/TypeScript/React production codebase to AI tools over three months. AI... canonical: https://daily.dev/posts/bgyuzkyom twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: I Let AI Rewrite 40% of My Codebase. Here’s What Actually Happened. | daily.dev og:description: A developer shares a first-hand account of delegating roughly 40% of a 60k-line Node/TypeScript/React production codebase to AI tools over three months. AI... og:url: https://daily.dev/posts/bgyuzkyom og:image: https://api.daily.dev/og/posts/BgYuZKYOM.png og:image:alt: Post cover image og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # I Let AI Rewrite 40% of My Codebase. Here’s What Actually Happened. **[Zero To Mastery](https://daily.dev/sources/zerotomastery)** · [@aldopaganijr](https://daily.dev/aldopaganijr) · 45 upvotes · 4 comments ## Summary A developer shares a first-hand account of delegating roughly 40% of a 60k-line Node/TypeScript/React production codebase to AI tools over three months. AI excelled at boilerplate, repetitive CRUD work, refactoring scaffolding, and expanding test coverage. Key failures included confidently wrong code (silent async errors, null assumptions, query inefficiencies), architectural drift from inconsistent patterns, and unnecessary overengineering. Development speed improved 30–40% for standard features and test coverage rose 18%, but code review intensity and maintaining architectural consistency became harder. The core takeaway: AI amplifies existing engineering judgment—strong fundamentals become a multiplier, weak ones accelerate hidden technical debt. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Community discussion Top comments from developers on daily.dev. **@eugeneyaremenko** · 6 upvotes > perform deep agentic revalidation of our plan **@gresakg** · 3 upvotes > Great article I can relate with. This quote is worth exposing: "It is leverage. And leverage amplifies both strength and weakness." ## Similar posts on daily.dev - [I Let AI Write My Code for 7 Days. Days 1–6 Were Magic. Day 7 Nearly Broke Me.](https://daily.dev/posts/i-let-ai-write-my-code-for-7-days-days-1-6-were-magic-day-7-nearly-broke-me--ohycaidt0) · Medium · 1 upvotes · 0 comments - [AI Isn’t Replacing Developers — It’s Changing What Good Developers Spend Time On](https://daily.dev/posts/ai-isn-t-replacing-developers-it-s-changing-what-good-developers-spend-time-on-ezxwvaq5i) · We Are .NET · 0 upvotes · 0 comments - [AI writes code faster. Your job is still to prove it works.](https://daily.dev/posts/ai-writes-code-faster-your-job-is-still-to-prove-it-works--zanf1p7hz) · Addy Osmani · 71 upvotes · 8 comments - [AI can 10x developers...in creating tech debt](https://daily.dev/posts/ai-can-10x-developers-in-creating-tech-debt-6avfrcy8v) · Stack Overflow Blog · 4 upvotes · 0 comments --- Tags: [#architecture](https://daily.dev/tags/architecture), [#typescript](https://daily.dev/tags/typescript), [#code-review](https://daily.dev/tags/code-review), [#technical-debt](https://daily.dev/tags/technical-debt) [View this post on daily.dev](https://daily.dev/posts/bgyuzkyom) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"DiscussionForumPosting","mainEntityOfPage":"https://daily.dev/posts/bgyuzkyom","headline":"I Let AI Rewrite 40% of My Codebase. 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